Muddy artificial seedlings

(1) Selection of muddy broodstock and breeding of mullet broodstock: First, capture from natural water bodies such as ponds, rice fields, lakes, etc.; second, purchase from the acquisition department of aquatic products; third, special pool cultivation. All three methods require the selection of loach. 1. Intimate choices In addition to being physically demanding, physically fit, healthy, disease-free, and normal in body color, the following points should also be noted: (1) Female 鳅 1 winter female has reached sexual maturity . Large individual females have large amounts of eggs, and the quality of the breeding seedlings is good. The growth is fast. Therefore, choose 2-3 years of age, body length is 10 cm or more, preferably 15-20 cm; weight is 18 g or more. Is 30-50 grams, abdominal swelling and soft and elastic, body color is orange with a shiny, abdomen white individuals. (2) The male must also choose 2-3 years of age, body length of 10 cm or more, preferably 15-20 cm; weight of 12 grams or more, preferably 20-40 grams, agile individuals. 2. Incubation of the intimacy should be done in a special pool after selecting the muddy broodstock. Before soaking, 20ppm tetracycline solution can be used to kill pathogens. The stocking rate should not exceed 200kg per 666m2 (ie, 1 mu). Fertilization should be strengthened. Keep the water neutral or slightly alkaline, and the water color is yellow-brown or green-brown. Can feed quail, fly maggots, livestock waste or lobster sauce, wheat bran and other bait. Add yeast powder and vitamins as appropriate. When the water temperature is 15-17°C, the animal protein content in the feed is controlled at about 10%, and the plant protein is about 30%. When the water temperature is above 20°C, the animal protein content is increased to 20%, and the plant protein content is reduced to 20%. Daily feeding is 5-7% of the loach's weight. 3. Identification of male and female relatives In the breeding season of loach, there are many different characteristics between males and females that can be identified by the naked eye in the above aspects: (1) The size of males is smaller, and the flanks on both sides of the dorsal fin end have fleshy projections; Larger beak, normal dorsal fin end, no meaty lumps. Egg-laying females have white spots on the body above the pelvic fins, while those who do not lay eggs do not. (2) The pectoral fins have larger pectoral fins, the second fins are the longest, the front ends are pointed, and the pointed part is upwards. The pectoral fins of females are smaller, and the front end is bluntly fan-shaped. (3) Before the abdomen spawns, the abdomen of the male and female is not hypertrophic and flattened. Before the female oviposites, the female abdomen is round and hypertrophied, and the color changes slightly pink with transparent yellow. (b) Loach breeding 1. Preparation before breeding (1) Preparation of spawning pool Spawning ponds for artificial propagation of domestic fish, or rice fields, ponds, and ditches, with water depths of 15-20 cm. Mesh sheets or bamboo fences can also be used as spawning sites to enclose 3 to 10 square meters of water. It would be better if microfluidics were maintained. In addition, concrete pools, large plastic boxes, buckets, tanks or other containers can be used as spawning facilities. Spawning sites must be disinfected before use, water depth of 20 cm when disinfected with quicklime, applied 15-20 grams per square meter. It can also be disinfected with bleach, applying 4 grams per square meter. (2) Preparation of the fish nest The fish nest should be made of materials that are soft and not easily spoiled and can float in the water, such as palm pieces, willow root beetles, golden horned algae, and agro grass. In recent years, soft green nylon braids have also been used. Woven into artificial fish nests 5 cm wide and 80 cm long. Before use must be disinfected: 2% concentration of salt water soak 20-40 minutes, can also be used 20ppm potassium permanganate soak for about 20 minutes; also available 10ppm malachite green soak 20-30 minutes, after soaking hang In the pool 10 centimeters away from the water, the top is shaded with reeds or grass. 2. The breeding mode of loach The breeding of loach has natural reproduction and artificial reproduction. (1) The natural reproduction is divided into two methods: complete natural reproduction and semi-natural reproduction. Completely natural reproduction, also called trapping and breeding, is a method of using artificial loach natural resources to artificially trap its spawning population and obtain fertilized eggs. First, during the spawning season, use muddy grass to prefer the habit of spawning in shoreline aquatic grasses, choose a secluded aquatic grassland area, first throw two baskets of ash in shallow water, and then apply 0.6-0.8 kg per square meter in the production area. Pigs, cattle, sheep and other animal dung. In this way, a large number of loach can be trapped to breed eggs in this area of ​​water grass. However, corresponding protection measures (prevention of enemies, etc.) must be taken for this natural area. Artificial fish nests can also be used to collect fertilized eggs in natural waters and move to specific containers for hatching, which can increase hatchability. Semi-natural reproduction is a method of letting mature muddy eggs spawn on their own under artificial conditions. It requires the construction of spawning ponds and hatchery facilities. Before breeding, spawning ponds and hatchery equipment must be sterilized for use. The proportion of males and females, such as males and females, is 1:2 or 1:3. If the male is only about 10 centimeters in length, the male to female ratio can be adjusted to 1:4, increasing the number of males. 7-10 groups per square meter can be placed to ensure normal breeding. The water temperature is stable above 18°C. The fish nests are tied to bamboo rafts and suspended in the middle or corners of the spawning pool so that the nests are submerged under the water. Due to the poor viscosity of muddy eggs, attention should be paid to checking and cleaning the dirt deposited on the fish nest so as not to affect the adhesion of the fertilized eggs. The loach usually lays eggs on the eyeful morning and spawns at about 10 o'clock in the morning. When the spawning is basically completed, the fish nests with egg granules are immediately moved to the hatchery or other hatchery for hatching, and new fish nests are replaced and replenished into the spawning pool to collect eggs that have not yet been laid. Intimate eggs. After the last batch of loach spawning, hatching can be performed in the spawning pool. However, the relatives in the spawning pond must be caught in order to prevent the eggs on the fish nest from being ingested and affect the emergence rate. (2) Artificial propagation and semi-artificial propagation The semi-artificial propagation uses the method of artificial production and natural reproduction. Select mature pro-fat, male and female ratio of 1:2 or 1:3. Injection of oxytocin: cesium or pituitary pituitary (referred to as PG) with 1-2 tails per tail; or chorionic gonadotropin (HCG) injected 800-1000 IU per tail, or luteinizing hormone-releasing hormone analogue (referred to as LRH-A). Each injection of 5-8 micrograms of each tail, regardless of which one of the above drugs, must be dissolved in saline, and the dose of the male fleas should be halved. Since the loach individuals are small, the amount of each loach injection should not exceed 0.5 ml, and 0.2-0.3 ml is appropriate to prevent body swelling or liquid spillage. Inject 4 stainless steel needles, 1 ml glass syringe (disinfected with boiling before use). In order to effectively control the depth of the needle, the needle can be as short as 0.2-0.3 centimeters long with a file, or put the hose at the base of the needle, so that the needle only exposed 0.2-0.3 cm tip to prevent the needle into the deep, stab wound Internal organs. The back part of the injection site is good, followed by the abdominal midline, chest and pelvic fins. Mud body mucous is much and very slippery, so as not to damage the body, it should be wrapped in wet gauze for injection. Needle angle: 30 syringes and carcass are preferred. Cocaine 0.1 grams can be dissolved in 50 kilograms of water formulated as anesthetic. Inducing pro-spawning anesthesia in the anesthetic, only 2 to 3 minutes to be anesthesia, this time more convenient injection, into the spawning pool, soon to wake up. After the artificial oxytocin is applied, the relatives are returned to the spawning pool. When the water temperature is at 25°C, it will take about 12 hours. When the water temperature is 27°C, it takes only about 9 hours to lay eggs and fertilize. The subsequent operation is the same as the semi-natural propagation method. Full artificial breeding: It is a method of inseminating artificial eggs on the basis of semi-artificial reproduction. 3. Mud hatching Fertilized eggs can be hatched indoors or outdoors, with static water hatching and flowing water hatching. Prior to hatching, the nest is immersed in 10 ppm of malachite green for 20-30 minutes with the eggs attached to it. Do not soak with concentrated salt solution. Pull out the unfertilized eggs. (1) Incubation in still water The fish nests with fertilized eggs are placed and hatched in hatching ponds, incubators or spawning ponds. The water quality requirements are fresh. 400-600 fertilized eggs per liter of water can be placed. Care should be taken to prevent the fertilized eggs from squeezing in one piece. If fertilized eggs are found to be squeezed each other, they must be separated by a method of mixing water or using straws to avoid oxygen deficiency. Affect the hatching rate. (2) Incubation of running water Incubating with flowing water or microfluidic water is to incubate the fertilized egg in an incubation tank, an incubator or a hatchery ring. 1 Nested Flowing Water Incubation The fertilized eggs are attached to the fish nest and placed in an incubation facility for microfluidic incubation. The flow rate should be suitable for eggs that are not attached to the nest. Each egg can contain 800-1200 eggs. 2 to the nesting water hatching fertilized eggs detacked or not detacked and grasp the flow rate into hatchery hatching. Normal hatching loops, hatching cylinders and other flowing water hatch eggs density of 800-1200 eggs per litre of water. During the incubation period to prevent cold waves and storms, you can cover the hatchery with plastic film before the onset of the cold wave, but leave air holes behind. Other warming methods can also be used for processing. The water temperature of hatching water should be controlled within 3°C. Mud fertilized egg hatching water temperature range of 18-31 °C, suitable water temperature of 20-28 °C, the optimum water temperature is 24-2 °C. The incubation time used varies with the water temperature and is negatively correlated. The hatching rate is compared with the same batch of eggs, 80% at a water temperature of 15°C, 94% at 20°C, and 98% at 25°C. (3) Seedling cultivation 1. Seedlings are used to cultivate freshly hatched loach. The body is transparent and can not be freely moved. It can only be attached to fish nests or other objects with the adsorber on the head, and the yolk of the abdomen as nutrient. After about three days, the yolk was absorbed and the seedlings were able to swim and start to feed. At this time, they should be transferred to the nursery stock. It is better to cultivate loach seedling soil pools than cement pools, because soil pools can better cultivate plankton, and provide more palatable opening baits for loach seedlings. The quality of earthen pond water is more stable than cement ponds. (1) Clear pond nursery seedling nursery pond area of ​​20-50 square meters, depth 30-40 cm. About 15 days before the seedlings are planted in the pond, the water is drained and exposed for 4-5 days. Then the quicklime is used for disinfection (50-75 grams per square meter), and then about 20-30 cm deep is injected into the new water. About 7 days after the application of lime, the medicinal properties disappeared, and livestock manure such as cow dung and pig manure was added to about 2 kg per square meter. After 3-5 days, you can put the seedlings into the pool. About 1,000 tails per square meter are provided for a still pool, and about 2000 pigs per square meter are replenished with microfluidic water or cages, and stocking specifications are neat. (2) Feeding and Fertilizing The seedlings are fed with cooked crushed egg yolk or fishmeal, or bean cake powder paste, 3-4 times a day. After feeding for 3-5 days, feed the leeches, rotifers, chopped silk cocoons or cocoons. Wait until the seedlings grow up slightly. At the beginning, the daily feeding amount accounts for 2.5% of the body weight, and the amount of feeding for the next day can increase to 10% of the total weight of the stocking. Muddy seedlings should be fertilized after being put into the pond. When the water temperature is low, 2 g of ammonium nitrate can be used per cubic meter of water, and when the water temperature is high, 2.5 g of urea is applied per cubic meter of water. Normally it is applied once every other day and continuously applied 2-3 times. Afterwards, fertilization concentration and interval time will be adjusted according to water quality. In the application of chemical fertilizers, combined with organic fertilizer, the effect is better. 2. After cultivating the seedlings for a period of one month, if they grow to more than 3 cm, they will be bred in separate ponds. (1) The area for pond cultivation is 20-60 square meters, the depth of pool is 30-40 centimeters, and there is good anti-escape facilities. Before the breeding, the field is disinfected and basal fertilizer is applied. After the seedlings were placed, rice bran (cooked), cakes, and silkworm cocoons were fed daily. The daily feeding amount and the number of feedings were managed in the later stage with the seedlings. There are 500 stocks per square meter, which can be up to 10 centimeters in the year of breeding. Per 1,000 m2, stocking up to 1000 mounds can also grow to 5-6 cm in length, and some can reach 8 cm. (2) Paddy fields should be cultivated with a small area of ​​paddy fields (below 100 m2), basal fertiliser before stocking, 50 kg per 100 m2, and 7.5-10 kg per 100 m2 in the early evening when new water is released after stocking. , fertilization, feeding alternately once a week. After 5 weeks, it can be administered every 2 weeks. When weeding in the paddy field in July, rice seedlings were interspersed with dry or rotten straw to cultivate the natural food of the earthworms. 3. Seedling cultivation and management, seedling cultivation and management, should pay attention to the following aspects: (1) to be equipped with special management, check daily escape, eating situation. (2) Always maintain good water quality. Take precautions against hypoxia, because the seedlings do not begin to intestine breathing until about two weeks after hatching. (3) Observe the changes in water quality and determine the amount of fertilization.